On Tue, 2022-11-01 at 11:25 +0530, KK CHN wrote: > I am trying WAL replication,the setup is working with a primary and Standby server. > > Query is : When the primary crashes due an unforeseen reason, > what may happen to the uncommitted transactions at primary ? Their effects remain invisible. > Those won't replicate to the standby right ? They may be replicated, but their effects will remain invisible there too. > How much data loss occurs in this case ? Data loss? I don't understand. There is no data loss with replication. If an incomplete transaction is rolled back, that is no data loss. > What is the mechanism to overcome this uncommitted transaction loss due to primary > server crash which is not replicated to the standby server ? I don't understand. Are you perhaps talking about failover? Yours, Laurenz Albe -- Cybertec | https://www.cybertec-postgresql.com